To prevent global warming, societies need to radically change how they extract, transform and use energy. Such long-term structural changes called energy transitions have occurred in the past, for example when coal replaced firewood, cars replaced horses and electricity replaced steam. But can future transitions to clear energy happen fast enough to avoid dangerous climate change? Should we strive for a world dominated by new and different clean energy systems or should we prepare to live with more conventional energy on a much warmer planet? To answer these questions, we need a dialogue between history, sociology of technology, energy system analysis, economics, and political science. We bring together scholars from different disciplines to discuss how the analysis of past and current energy transitions can inform future ones.